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--> black.

Flatboarder, great job, look forward to seeing it finished.

Hi everyone,
I'm just wondering what's the advantage or disadvantage thereof, for replacing the rear wheel to an 18inch. I use my bike (XT660R) 50/50 and here in northern Mexico, the terrain is very rough and dry. Lots of sand, gravel and very, very sharp rocks...

Thank's in advance for any comment.

Salud amigos !

hi i guess the main reason for a 18'' rim is for competition use, michelin deserts i believe don't come in 17'' a lot of offroad race tyres are just not made in that size
and mousses are again 18'' though if you are using tyre balls that should not be a problem.

As Stoic says, there is a wider choice of (tougher) off-road tyres, the option to run mousses (which in the terrain you describe would seem ideal), plus the benefit of extra ground clearance and rolling circumference as the wheel diameter is greater.

The only real downside (other than the cost of a new wheel) is that on the XT's, the speed reads off the gearbox, so your speedometer reading will be incorrect...

J xx

But then, speedo displacement is 10% and would only improve with 18" rear wheel as long as sprockets are kept same. I did not see a problem here.
Phil

True, but then it's like having a six speed gearbox with no first gear... you have to gear the 18" wheel down considerably to get the gearing back to anything remotely usable off-road...

The stock bike is 15/45, and I'm now running 14/50 (although 14/48 is probably closer to the original gearing with a 17 inch wheel)... hence the speedo is now completely out!

J x

Went to the bike shop to get a clutch lever and they told me $93 bucks aussie. Anyone know of any after market ones?

Yes sure, but this would also happen when gearing down a 17" stock tenere for offroad usage. Speedo would become useless. I guess, when not using an IMO at all, one needs to consider a speedohealer or similar device.

Speedo displacement is one of those issues, I totally dislike with my two Yamahas. The WR250R is even worse than the Tenere. I realize up to 12% of displacement with worn down stock rear tire. The numbers displayed are useless (and even illegal! 10% of displacement is the legal limit in Germany as to my knowledge). The WR250R at least offers an adjustable odometer mode for enduro racing or whatever.

In my opinion these digital instruments should be as exact as possible. There is no technical need for any displacement at all. Numbers are acurate. Even worse, for offroad usage there is considerable displacement anyway, due to rear wheel spin all the time. This would not happen at all with speed sensor at front wheel.

Those devices should be adjustable (at least with dealer interaction) for any sort of modifications of motorcycles. I still cannot believe, transmission ratio and tire size is hardwired in these devices. There must be some way to adjust it.

Since I am using a GPS mostly, speed display does not matter that much, but odometer should definitely be acurate. However, strange enough, odometer displacement is only about half or one third of speedometer displacement, which again puts some questions at use of speedhealer (which ratio to adjust).


---> Late update: all of these speedo issues have already been addressed right here (surprise): http://www.xt660.com/showthread.php?t=8876.

Phil

Front wheel installed
 

3 more low quality pictures shot by mobile phone:
new front wheel with Magura radial caliper and Spiegler disk.
The adapter for caliper installation is a preliminary prototyp to determine detailled specification for final version. Rear wheel has not yet been built at this moment.

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